<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    .wrap{
        width: 400px;
        height: 30px;
    }
    span{
      background: url("images/搜索.png") no-repeat;
      display: inline-block;
      width: 30px;
      height: 30px;
      background-size: 30px;
    }
    </style>
</head>
<body>
    <div class="wrap">
     <span></span>
    <input type="text">
    </div>
</body>
</html>